In 6.0 sendmail, /etc/mail/ip_allow is used to control who's
allowed relaying. In 6.1 sendmail, /etc/mail/allow is used.
Upgrade tries to preserve the settings from ip_allow but
fails and generates an incorrect setting, breaking relaying.
Example: Before upgrade, /etc/mail/ip_allow contains two
lines
192.168.
10.
After upgrade, /etc/mail/access contains the two lines
2 RELAY
2 RELAY
This is incorrect. /etc/mail/access should contain
192.168 RELAY
10 RELAY
after the upgrade.